From HaskellWiki

The Haskell implementors' workshop is a forum for those involved in
implementing Haskell systems, infrastructure, libraries and tools,
generally for people involved in implementing Haskell technology, to
share their work and discuss future directions and collaborations with
others.

In 2014, the Haskell Implementors Workshop will be co-located with ICFP 2014 in Gothenburg.

The workshop does not have proceedings. Talks and/or demos are proposed by
submitting an abstract, and selected by a small program committee.
The workshop will be informal and interactive, with a flexible timetable
and plenty of room for ad-hoc discussion, demos, and impromptu short talks.

We are aiming for 20 minute talks with 10 minutes for questions and
changeovers. We want to hear from people writing compilers, tools, or
libraries, people with cool ideas for directions in which we should take
the platform, proposals for new features to be implemented, and
half-baked crazy ideas. For more details see the Call for Contributions in full.

The workshop will also give opportunity for lightning talks organised on
the workshop day.
These talks will be 5-10 minutes, depending on available time, and do not
require prior proposal submission.